Earlier quoted context omitted.
Because I don't want to be associated with companies that break the law and violate regulations knowingly. I've long had a reputation of integrity, and it's one of the few things I have left having almost nothing else.
So you would rather be known as someone who had an opportunity to report a violation, and chose not to? From my perspective it seem like you decided against acting with integrity in this situation - the moral thing would have been to report the violation, but you chose to look the other way and resign.
I agree with this statement.
This isn't a judgement, we all have to make choices; the "right" choice (the one that aligns with integrity) is usually the one that will be the least self-serving and even temporarily harmful. They did what was right for them, that's okay, but it was not the choice of integrity.